The shredding of scrapped vehicles for breaking down materials has been known for a long time. In carrying out the shredding method, method controls have been established in which the material mixture produced is divided up into different fractions. Thus, a so-called shredder light fraction (SLF) is initially separated from the material mixture produced, using a suitable suction device. The remaining fraction is subsequently separated into a ferromagnetic fraction (shredder scrap (SS)) and a non-ferromagnetic fraction (shredder heavy fraction (SHF)), using a permanent-magnet separator. The portion of the metallurgically fully usable shredder scrap-metal fraction is often approximately 50 to 75 wt. %. Existing designs generally provide for the shredder light fraction being disposed of as waste or burned in waste incinerators. It is characterized by both a large fraction of organics and a large fraction of fine-grained material. The heavy fraction, which is not able to fly and is not ferromagnetic, i.e., the shredder heavy fraction, is distinguished by a high percentage of nonferrous (NF) metals. Special sorting systems have been developed for recovering the different NF metals, where, however, the remaining residue of organic and inorganic, non-metallic components is generally disposed of as waste. In the following, shredder residues should be understood as all material streams from the shredding process, which may not be directly removed at the shredder as products that are metallurgically directly utilizable (shredder scrap).
Described in German Published Patent Application No. 44 37 852 is a method, in which the shredder light fraction is sorted to remove “unwanted components”, in particular copper and glass. In this context, the shredder residues are homogenized and mixed in a compulsory mixer with a fine-grained to superfine-grained material containing a magnetizable component, and the resulting mixture is conveyed through a magnetic separator. In this context, the metallic components of the shredder light fraction, which impede metallurgical use, can be separated out in this manner.
European Published Patent Application No. 0 863 114 describes the production of a permanently plastic, backfilling material for mines, by adding an adhesive component, a filler, and a salt solution to the shredder light fraction. This is intended to provide a pressure-resistant, permanently plastic body.
It is described in German Published Patent Application No. 197 42 214 that the shredder light fraction is shredded further and subjected to a thermal treatment. During or after shredding, metallic components should be sorted out and the remaining mixture of materials should be melted in a smelting reactor and converted to a “harmless” solid by cooling it.
In addition, European Published Patent Application No. 0 922 749 describes a method for processing the shredder light fraction, where the shredder light fraction is a calcined in a fluidized-bed gasifier amid the introduction of calcium carbonate.
In a further, thermal process, German Published Patent Application No. 197 31 874 describes the shredder light fraction being compressed again in a further step, and then shredded, homogenized, and reduced in water content, in order to be thermally utilized in a subsequent step.
European Published Patent Application No. 0 884 107 describes for the shredder light fraction being converted into a metal-free fraction having a shredding size of ≦20 mm, by shredding, classifying, and sorting it. The sorting of the shredder light fraction should result in a thermally utilizable fraction.
In addition to the utilization methods, it is conventional that the shredder light fraction can be subjected to a pretreatment, in which residual ferromagnetic fractions of iron, stainless steel, and aluminum are separated. Similar methods have also been used for sorting the shredder heavy fraction. Furthermore, it is conventional that polyolefins can be separated from this fraction.
What the methods have in common is, that they are each only designed for processing the shredder light fraction or the shredder heavy fraction. Joint processing is not provided. In addition, the methods are not suitable under the aspect of maximizing the degree of use in the order of material use, raw-material use, and energetic use. Against the background of increasing legal requirements (EU End of Life Vehicles Directive, EU Directive on Incineration of Waste, and others), as well as increasing landfill costs and requirements for the material to be landfilled, a higher utilization rate may be desirable. Thus, the German regulation on end of life vehicles of Apr. 1, 1998 provides for over 95% of a scrapped car by volume having to be utilized as of the year 2015. In addition, increased requirements from the EU Scrapped Car Guideline passed in September, 2000 specify that the fraction of material streams utilizable as materials and raw materials for mechanical and feedstock recycling should be increased to at least 85%. Thus, utilization excludes the use as energy only, e.g., in waste incinerators.
Therefore, it is an object of the present invention to provide a method and a system by which the shredder residues may be jointly processed, and separated in a mechanical sorting process into end products usable for materials, raw materials, and energy recovery. In particular, the joint processing may allow the portion of the unusable fraction to be reduced to less than 5% of the total weight of the scrap vehicle, and allow the portion of end products usable as materials or raw materials to be increased.